diff --git a/pom.xml b/pom.xml
index a215e2a818f..0d74b56a455 100644
--- a/pom.xml
+++ b/pom.xml
@@ -88,7 +88,7 @@ under the License.
     <parquet.version>1.16.0</parquet.version>
     <parquet.maven.scope>provided</parquet.maven.scope>
     <hadoop.version>3.3.4</hadoop.version>
-    <arrow.version>18.3.0</arrow.version>
+    <arrow.version>19.0.0</arrow.version>
     <codehaus.jackson.version>1.9.13</codehaus.jackson.version>
     <spotless.version>2.43.0</spotless.version>
     <!-- semanticdb-scalac is published per Scala patch version, so the 2.13 profiles need a
diff --git a/spark/src/main/java/org/apache/arrow/c/ArrowImporter.java b/spark/src/main/java/org/apache/arrow/c/ArrowImporter.java
index 94c4916f9f1..1485faf0ba2 100644
--- a/spark/src/main/java/org/apache/arrow/c/ArrowImporter.java
+++ b/spark/src/main/java/org/apache/arrow/c/ArrowImporter.java
@@ -60,6 +60,11 @@ public FieldVector importVector(
       vector = field.createVector(allocator);
       ArrayImporter importer = new ArrayImporter(allocator, vector, provider);
       importer.importArray(array);
+      // Arrow Java 19 stopped closing the source struct once its contents move into the importer's
+      // copy (GH-765), so free it here; earlier versions closed it already.
+      if (!array.isClosed()) {
+        array.close();
+      }
       return vector;
     } catch (RuntimeException | Error failure) {
       if (vector != null) {
@@ -68,9 +73,9 @@ public FieldVector importVector(
       if (field != null) {
         closeDictionaries(field, provider, failure);
       }
-      // ArrayImporter.importArray moves the array into a copy it owns and closes the source
-      // before doImport can fail, so a closed array means the importer already took it and
-      // releasing it again would be a double release.
+      // ArrayImporter.importArray moves the array into a copy it owns before doImport can fail, so
+      // the source's release callback is already cleared and release() is then a no-op. Earlier
+      // Arrow versions also closed the source, and a closed array must not be released again.
       if (!array.isClosed()) {
         AutoCloseables.close(failure, array::release, array);
       }
diff --git a/spark/src/main/scala/org/apache/spark/sql/comet/util/Utils.scala b/spark/src/main/scala/org/apache/spark/sql/comet/util/Utils.scala
index 975d4b05823..8bfb46c94cc 100644
--- a/spark/src/main/scala/org/apache/spark/sql/comet/util/Utils.scala
+++ b/spark/src/main/scala/org/apache/spark/sql/comet/util/Utils.scala
@@ -789,7 +789,7 @@ object Utils extends CometTypeShim with Logging {
       if (numValues > 0) {
         // An Arrow Java vector has no array offset, so validity bit i belongs to value i even when
         // the offsets start past zero, and the bitmap is copied from bit 0.
-        val validityBytes = BitVectorHelper.getValidityBufferSize(numValues).toLong
+        val validityBytes = BitVectorHelper.getValidityBufferSizeFromCount(numValues).toLong
         narrow.getValidityBuffer.setBytes(0, large.getValidityBuffer, 0, validityBytes)
         val offsets = narrow.getOffsetBuffer
         (0 to numValues).foreach { i =>
diff --git a/spark/src/test/scala/org/apache/spark/sql/comet/util/UtilsSuite.scala b/spark/src/test/scala/org/apache/spark/sql/comet/util/UtilsSuite.scala
index 29c4547ccd3..64e8a651386 100644
--- a/spark/src/test/scala/org/apache/spark/sql/comet/util/UtilsSuite.scala
+++ b/spark/src/test/scala/org/apache/spark/sql/comet/util/UtilsSuite.scala
@@ -301,12 +301,11 @@ class UtilsSuite extends CometTestBase {
   }
 
   test("serializeBatches writes empty large-offset vectors with 32-bit offsets") {
-    // A vector that holds no values need not have an offset buffer, so none is read.
+    // A vector that holds no values need not have an offset buffer, so none is read. Arrow 19's
+    // setValueCount(0) allocates one, so the test leaves the vectors unallocated.
     val strings = new LargeVarCharVector("s", CometArrowAllocator)
     val binaries = new LargeVarBinaryVector("b", CometArrowAllocator)
     try {
-      strings.setValueCount(0)
-      binaries.setValueCount(0)
       assert(strings.getOffsetBuffer.capacity == 0)
       val batch = new ColumnarBatch(Array(cometVector(strings), cometVector(binaries)), 0)
       assert(
@@ -487,7 +486,8 @@ class UtilsSuite extends CometTestBase {
     val width = BaseLargeVariableWidthVector.OFFSET_WIDTH.toLong
 
     val validity =
-      CometArrowAllocator.buffer(BitVectorHelper.getValidityBufferSize(values.length).toLong)
+      CometArrowAllocator.buffer(
+        BitVectorHelper.getValidityBufferSizeFromCount(values.length).toLong)
     val offsetBuffer = CometArrowAllocator.buffer(offsets.length * width)
     val data = CometArrowAllocator.buffer(offsets.last)
     val buffers = Seq(validity, offsetBuffer, data)